Selecting Accurate Emission Factors

• 14/05/2024
• 4 minutes to read

When assessing a company’s carbon footprint, it is essential to ensure the accuracy of the results so that decision-making is based on precise, actionable information. One way to achieve this, beyond proper calculations and feeding accurate activity data into the system, is by selecting the most suitable emission factors.

Continia Sustainability provides a diverse array of integrated emission factor databases, providing users with the flexibility to choose from provided values or import custom emission factors into the system. Whether opting for pre-existing data or personalized factors, the following guide offers insights into confidently selecting the right emission factors for achieving precise results.

By following the following key steps and considering quality factors, organizations can make informed choices in selecting emission factors, ensuring accuracy and reliability in carbon footprint assessments.

Key steps for choosing emission factors¹:

1. Source selection - use reliable and relevant sources:

   • Prioritize specific sources - opt for emission factors tailored to your suppliers or products when possible. Ensure these factors adhere to recognized standards such as the GHG Protocol, ISO 14064-1:2018, or PCAF. Engaging with stakeholders such as suppliers and customers can provide insights and access to more relevant emission factors, fostering informed decision-making.
   • Use government and international sources - if supplier-specific factors are not available, use emission factors published by government or international agencies and organizations (e.g., EPA, IPCC, IEA). Choose sources that align geographically with your activities and imports, giving precedence to local factors when available, especially for resources such as electricity.
   • Industry-specific values - if neither supplier-specific nor general sources are available, refer to industry-specific values.
   • Conduct research - if no specialized sources are accessible, conduct thorough research to identify relevant emission factors.

2. Consistent databases - prioritize using a database that covers your entire footprint to ensure consistency in the methodologies used for your emission factors. Exercise caution when combining factors from different databases to prevent the blending of methodologies, boundaries, or limits, which may result in the double counting of emissions (e.g., transportation of goods).

3. Quality considerations - to ensure the accuracy and reliability of emission factors, consider the following factors to make informed decisions:

   • Currency - make sure to use the most recent version of emission factors to ensure accuracy.
   • Activity units alignment - match activity data with appropriate units for precise calculations.
   • Choose activity-based data over monetary measures - prioritize activity-based data over monetary measures to mitigate the impact of inflation.
   • Comprehensive gas coverage - choose emission factors that cover a broad range of Kyoto Protocol gases.
   • Lifecycle coverage - for products purchased by your organization, prioritize upstream "cradle-to-gate" coverage over full "cradle-to-grave" assessments.
   • Regular assessment - if you employ custom or imported emission factors, periodically review for updates or revisions. Document sources meticulously to enhance transparency and justify selections.